The present invention relates generally to chucks for use with drills or with electric or pneumatic power drivers. More particularly, the present invention relates to a chuck of the keyless type which may be tightened or loosened by hand or by actuation of the driver motor.
Both hand and electric or pneumatic tool drivers are well known. Although twist drills are the most common tools on such drivers, the tools may also comprise screw drivers, nut drivers, burrs, mounted grinding stones, and other cutting or abrading tools. Since the tool shanks may be of varying diameter or of polygonal cross section, the device is usually provided with a chuck that is adjustable over a relatively wide range. The chuck may be attached to the driver by a threaded or tapered bore.
A variety of chucks have been developed in the art. In an oblique jawed chuck, for example, a chuck body includes three passageways disposed approximately 120xc2x0 apart from each other. The passageways are configured so that their center lines meet at a point along the chuck axis forward of the chuck. The passageways constrain three jaws that are moveable in the passageways to grip a cylindrical or polygonal tool shank displaced approximately along the chuck center axis. The chuck includes a nut that rotates about the chuck center and that engages threads on the jaws so that rotation of the nut moves the jaws in either direction within the passageways. The body is attached onto the drive shaft of a driver and is configured so that rotation of the body in one direction with respect to the nut forces the jaws into gripping relationship with the tool shank, while rotation in the opposite direction releases the gripping relationship. The chuck may be keyless if it is rotated by hand. Examples of such chucks are disclosed in U.S. Pat. Nos. 5,125,673 and 5,193,824, commonly assigned to the present assignee and the entire disclosures of which are incorporated by reference herein. Various configurations of keyless chucks are known in the art and are desirable for a variety of applications.
When using a chuck to drill masonry, dust from the drilled hole may move into the chuck""s central bore. Dust moving into the jaw passageways may adhere to the greased jaw threads and nut threads, thereby tending to inhibit the chuck""s operation.
The present invention recognizes and addresses the foregoing considerations, and others, of prior art constructions and methods.
Accordingly, it is an object of the present invention to provide an improved chuck.
It is a further object of the present invention to provide an improved power driver.
These and other objects are achieved by a chuck for use with a powered driver having a rotatable drive shaft and a cooling fan. The chuck includes a generally cylindrical body having a nose section and a tail section. The tail section is configured to rotate with the drive shaft. The nose section has an axial bore formed therein. The body defines an air passageway extending through the body between axial bore and an area about the tail section. A generally cylindrical first sleeve is disposed about the body. The first sleeve substantially encloses the area and is configured to extend to a housing of the drill so that air from the fan is forced into the area, through the air passageway and into the axial bore.
In another embodiment, the present invention includes a powered driver having a housing, a rotatable drive shaft, a cooling fan and a motor in rotationally driving engagement with the drive shaft and the cooling fan. The driver also includes a chuck having a generally cylindrical body with a nose section and a tail section. The tail section is configured to rotate with the drive shaft, and the nose section has an axial bore formed therein and a plurality of jaw passageways formed therethrough and intersecting the axial bore. The body defines an air passageway extending through the body between the axial bore and an area about the tail section. A plurality of jaws are movably disposed in the jaw passageways. A generally cylindrical first sleeve is disposed about the body. The first sleeve substantially encloses the area and is configured to extend to the housing so that air from the fan is forced into the area, through the air passageway and into the axial bore.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one or more embodiments of the invention and, together with the description, serve to explain the principles of the invention.